Cold darkroom warm chemicals

Steve Roberts · Jan 30, 2006

I use a seed propagator heater in winter. It just happens to keep the developer at 68 degs, give or take a bit, and cost 50p at a car boot sale. Perhaps this should have gone in the recent "Frugal photographer" thread!

Steve

Jim Noel · Jan 31, 2006

Many aquarioum stores carry two major types of heaters. The most common is like a cigar tube which hangs on the side of an aquariom and thus requires more chemical depth in order to function.
The second type is about the size of a credit card and only 2-3 times as thick. It is covered with a rubbery plastic and is best used lying flat on the bottom of the tray. It is necessary to get one made to operate in the appropriate temperature range.

Black Dog · Jan 31, 2006

Wasn't 'cold darkroom warm chemicals' a Tom Waits track? Sounds like it should be?

Wayne · Jan 31, 2006

Jim Noel said:
Many aquarioum stores carry two major types of heaters. The most common is like a cigar tube which hangs on the side of an aquariom and thus requires more chemical depth in order to function.
The second type is about the size of a credit card and only 2-3 times as thick. It is covered with a rubbery plastic and is best used lying flat on the bottom of the tray. It is necessary to get one made to operate in the appropriate temperature range.

Things seem to be changing rapidly in the field of aquarium heaters. The glass one I bought just five years ago looks like a dinosaur, and it is only for vertical use. The one I bought last week is one of the cigar types, but of stainless steel and it can be used horizontally. Mine just lays down in the groove in the 11x14 tray so not a huge amount is needed to cover it. I would guess its only 2.5 or 3 liters, but since its only water I have had no need to measure it. I've used it 3-4 times now and I love it. Best 12 dollars I ever spent.

leeturner · Feb 1, 2006

Jim Noel said:
Many aquarioum stores carry two major types of heaters. The most common is like a cigar tube which hangs on the side of an aquariom and thus requires more chemical depth in order to function.
The second type is about the size of a credit card and only 2-3 times as thick. It is covered with a rubbery plastic and is best used lying flat on the bottom of the tray. It is necessary to get one made to operate in the appropriate temperature range.

I had a look at the credit card sized ones as they tend not to blow if taken out of the water. The one I looked at heated liquid 2 degrees warmer than the ambient temperature, so if it's only 15 degrees in the room it's not going to do much.

Nick Zentena · Feb 1, 2006

If you're sitting bottles in the heated water or a second tray extra water is a positive. The greater the amount of water the steadier the temp will stay.

craigclu · Feb 2, 2006

I picked up a cheap ($7) aquarium heater at Walmart and tried it tonight. It's a 7.5W, cylinder shape that's designed for 3-5 gallon aquariums. I had some developer from a previous session in a covered tray (11X14). The heater didn't have enough energy to change the ambient temperature after about 45 minutes. I added some more developer at 1:3 with hot water to raise the tray temperature and by the time I was done printing, the tray was 3º cooler than when I started. I thought I'd share this in case someone was considering the same thing. It appears that this model doesn't have the capacity for what I was doing with it (that, or it simply wasn't working?).

Wayne · Feb 2, 2006

My 75 watt unit takes 1.5 or 2 hours to bring the 11x14 tray up to temp if it starts at about 50. But then it holds it perfectly to +/- 1 degree. I was worried it might be too powerful but its about right for my purposes. A much more powerful one might require a circulating pump. I have to turn the heat on in the darkroom a couple hours ahead of time anyway, so I just throw cold water in the tray and walk away. If I'm in a bigger hurry to start I can just use 68 degree water.

.

seadrive · Feb 2, 2006

I bought a washable heating pad, with three heat settings. It's made by Cara, and cost me $25.99 at the local five and dime.

Tried it out the other night. The ambient temperature was about 50 F, so I put it on the highest setting. The starting water temp was 65, and after an hour, it had risen to 72. So I turned it down to the medium heat setting, which worked great, maintaining about 68 degrees F.

The pad is not very large, so it can only heat one tray (the developer, of course).

I'm not worried much about the stop bath, but... anyone know if fixer becomes ineffective below a certain temperature?

Wayne · Feb 2, 2006

I dont think a few degrees difference between developer and stop/fix will cause any problems, but you dont want it to be excessive. I wouldnt want my stop/fix to be in 50s, that kind of temperature shock cant be good for the emulsion.
Cooler temps may mean you need to fix longer, exactly how long would probably be a question for the maker of your fix. My fixer and stop probably stay in the mid 60's, though I havent checked. Keeping them there shouldnt be hard except in a very cold darkroom, in which case you'd probably want to get 3 heaters.

hoginthesky · Feb 17, 2011

Do you think on of these vivarium heaters for reptiles will work?? Looks absolutely perfect for my 10x8 trays (the 35"x11").

http://www.netpetshop.co.uk/p-27520-algarde-reptile-vivarium-heat-mat.aspx

Do you think it would be good to get a thermostat or would it not be needed? It is cold in my darkroom! temperature drops to 12C (53F) and so do the chemicals...

Wayne · Feb 17, 2011

Dunno. I'm still using the same heater as before with great results.

removed account4 · Feb 17, 2011

i just put warm water in my sink and warm water in a tray so the cold chems in a 2 layer water jacket
been like this for a long time, seems to work fine ...

Mainecoonmaniac · Feb 17, 2011

How about a heaters that's used for starting seedlings it's 2' wide by 9' long. It runs $65.

http://www.kalyx.com/store/proddetail.cfm/ItemID/997954/CategoryID/12000/SubCatID/2760/file.htm

holmburgers · Feb 17, 2011

I like the idea of a hot plate underneath the trays. The other day I saw a large (4' x 16" maybe) serving hot plate at an antique mall with a variable thermostat.

My sink is too small to use as a water bath, though if a tray gets cold I can heat it up in the sink, but it's not convenient to leave it in there.

Cold darkroom warm chemicals

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